1. Field of the Invention
The present invention relates generally to a method for fabricating a quantum dot and an application of the same. More particularly, the present invention relates to a method for fabricating a quantum dot by using a dielectric thin film pattern and a heat treatment process and a semiconductor structure containing the quantum dot fabricated through the method.
2. Description of the Related Art
A semiconductor quantum dot is a semiconductor structure obtained by selecting a material having a narrow bandgap from between two materials having bandgaps different from each other and growing the material in the other material having a wide bandgap to the extent that the material has a size corresponding to the de Broglie wavelength. The quantum dot has a bandgap that may three-dimensionally confine the motion of electrons and holes serving as carriers in a semiconductor. When comparing with bulk materials that do not confine the motion of the carriers, the quantum dot has unique and superior electric and optical characteristics. Thus, the studies and research to apply the quantum dot to semiconductor devices, such as an infrared detector, a laser, a light emitting diode, a transistor and a solar cell, have been actively pursued. Especially, single quantum dots, in which the quantum dots represent the same optical characteristics, have been applied as nano-electronic devices and nano-optical devices for single electron memories and single photon light sources. Among the nano-optical devices, a single photon emitter is a representative light source employing the single quantum dot. The single photon emitter is a very important element to realize the quantum cryptography or the quantum computer.
When a nano-device is fabricated by using the quantum dot, it is very important to control a position, a size and a concentration of the quantum dots. In general, according to the related art, a quantum well structure is etched or the S-K (Stranski-Krastanov) mode is used to spontaneously grow the quantum dots. However, when the etching scheme is employed, defects may occur due to the irregular atom arrangement at an edge of the quantum well structure. In the case of the growth scheme by using the S-K mode, it is difficult to accurately adjust the growth conditions, so the size, concentration and growth position of the quantum dots may not be precisely controlled.